As is well known, various liquids are contaminated by organic materials. For example, used lubricating oil frequently includes organic materials comprising products of combustion. Waste water is almost always contaminated by organic materials such as human and animal waste, decaying vegetable materials, etc.
As is also well known, organic contaminants can be removed from liquids by exposing the contaminated liquids to oxidizing agents, particularly oxidizing gases. Ozone and chlorine dioxide are among the most potent of the oxidizing gases, and therefore offer tremendous potential with respect to the removal of organic contaminants from used lubricating oil, waste water, and other liquids. Unfortunately, the inherent instability of ozone and chlorine dioxide has heretofore prevented the commercial utilization thereof in the removal of organic contaminants from liquids.
The present invention comprises a method of and apparatus for utilizing oxidizing gases to remove organic contaminants from liquids which overcomes the foregoing and other problems long since associated with the prior art. In accordance with the broader aspects of the invention, the oxidizing gas is utilized at its source and is formed into sub-micron size bubbles which are dispersed into a flowing liquid to be decontaminated. Due to the sub-micron size of the bubbles, the surface area of the oxidizing gas is greatly increased, thereby greatly increasing the efficiency of the gas in oxidizing organic contaminants from the liquid.
In accordance with a first application of the invention, an oxidizing gas is selected from the group including ozone and chlorine dioxide. The oxidizing gas is formed into sub-micron size bubbles by directing it through a sintered stainless steel or glass tube. Used lubricating oil is caused to flow past the exterior of the stainless steel or glass tube. The flowing liquid cleaves sub-micron size bubbles of the oxidizing gas from the surface of the stainless steel tube. The sub-micron size bubbles of oxidizing gas are dispersed into the used lubricating oil, whereupon organic contaminants contained within the used lubricating oil are efficiently oxidized.
In accordance with a second application of the invention, an oxidizing gas is selected from the group including ozone and chlorine dioxide. The oxidizing gas is formed into sub-micron sized bubbles by directing it through a sintered stainless steel or glass tube. Waste water is caused to flow past the exterior of the stainless steel tube. The flowing liquid cleaves sub-micron size bubbles of the oxidizing gas from the surface of the stainless steel tube. The sub-micron size bubbles of oxidizing gas are dispersed into the waste water, whereupon organic contaminants contained within the waste water are efficiently oxidized.